1. Field of Invention
The present invention relates to an integrated circuit device structure and a manufacturing method thereof. More particularly, the present invention relates to a bonding pad structure and a manufacturing method thereof.
2. Description of Related Art
As semiconductor technologies continue to advance, deep submicron devices are now routinely manufactured. Due to a reduction in feature size, many formerly minor technical problems now become prominent and demand special consideration. For example, quality of connection between a bonding pad and a bonding wire can seriously affect the reliability of a device.
As dimensions of a device shrink, contact area between a conductive wire and a bonding pad is reduced correspondingly. Hence, when a wire is attached to a bonding pad, the bonding pad has to support a larger stress. Furthermore, adherence of the bonding wire to the bonding pad is likely to drop due to a smaller junction area. In general, a conventional bonding pad has a very flat surface. FIG. 1A is a cross-sectional side view of a conventional bonding pad. As shown in FIG. 1A, the bonding pad 110 is formed over a substrate 100. A passivation layer 120 is formed over the substrate 100 and the peripheral region of the bonding pad 110.
FIG. 1B is a cross-sectional side view of a conventional bonding pad 110 with a bonding wire 150 attached to the bonding pad surface. In general, contact area between a conductive wire and a bonding pad in a highly integrated circuit chip is very small. Therefore, the conductive wire can be easily pulled off causing low production yield.